This adds a simple navigation bar since web browser are apparently dumbler than most Gemini browsers. The "Root" link points to the capsule' root, "Home" to the current home directory and "Up" to the parent directory. Users home are discovered using a simple heuristics: ~user path components.

diff from Josiah Frentsos, thanks!

this code is now part of Game of Trees too!

This allows to ship a pre-compiled fragments.c in the tarball and not building the template executable. The same thing already happens with yacc and parse.y.

needs unveil too now.